This is a project for people a little bit skilled in soldering and design PCB. The user [dernulleffekt] designed an homemade shield for Raspberry Pi that integrate an Arduino Board.

The Paper-Duino-Pi is an Arduino shield for the Raspberry Pi. Due to the fact that it is designed as Paper-PCB it is easy to create and one doesn’t need a printed circuit board. Some small modificaten in the OS and IDE and you have a perfect interface for the Raspberry Pi.

This shows how one can use it with the Firmata and Pure Data. On the [website] there is a very well written tutorial to build your Raspberry/Arduino shield at home.